1. Field of the Invention
The present invention relates to a method and apparatus for making clear ice. More specifically, the invention relates to a method and apparatus for making clear ice using a minimum amount of water, particularly in connection with commercial and industrial ice making machines.
2. Related Art
One of the most desirable features of manufactured ice is that it be as clear as possible. Obtainment of highly clear ice is becoming increasingly more difficult to accomplish because of the deteriorating quality and the increasing hardness (as measured by mineral content) of the commercial water supply in all parts of the country.
The minerals and chemicals which are normally found in the commercial water supply will adversely affect its clarity, and will reduce the firmness of the ice. Water tends to freeze pure and clear and leave the minerals and chemicals concentrated behind in the remaining unfrozen water. Circulating or agitating the water on the ice-making surface serves to improve the efficiency of this separation process. In addition, it is necessary to bleed-off a certain portion of the surplus water containing the concentration of minerals and chemicals from the freezing process in order to maintain the hardness of the water at an acceptable level, so that the freezing of clear ice can continue.
Normally, the best procedure for achieving ice that is as clear as possible is to bleed-off a certain portion of the water being frozen, either on a continuous basis during the complete freezing cycle or all at once during the harvest cycle, in order to dispose of the minerals and chemicals. It has been the practice in the ice industry to supply water for freezing from a sump to the evaporators where the freezing is effected while concurrently adding water to the sump so that it remains full at all times. One of the major concerns arising from the aforementioned procedure is the fact that a large amount of water must be bled-off in order to get rid of the minerals and chemicals. Consequently, there must be substantial waste water expense and moreover, the energy employed in refrigerating the waste water prior to disposal is quite substantial since the bled-off water has been chilled to a temperature in the range of 32.degree. F. to 35.degree. F.
It is the solution to the foregoing and other problems to which the present invention is directed.